Transformer / Wire Calculation

[Train nut]

Please excuse the stupid question on my first post. I have been an electrician for 17 yrs., but do not know how to figure wire size in regards to transformers. For example, I have a 25 kVA transformer 3p 240V to 120/240V 1p. How can I tell what wire size to use?:-?
Thank you much

 

[jtester]

Train Nut

There is no such thing as a 25 kva 240v 3 phase to 120/240 volt single phase transformer. Could you give us a different example, or clarify your application?

Jim T

 

[Train nut]

I apologize. I did mean 230V primary.
The engineer's note reads verbatim:
' 25kVA, 230V 1phase transformer Primary 240V, 3ph - Secondary 240/120 1ph'

Thanks